1. Field of the Invention
The present invention relates to refiners for refining a fiber suspension, and, more particularly, to a tackle which is coupled with a disk within the refiner.
2. Description of the Related Art
A paper-making machine receives a fiber suspension which is prepared from a source of fiber, such as wood, and manufactures a fiber web, such as a paper web. The fiber source within the fiber suspension must be broken down into individual fibers which are maintained in a deflocculated state within the fiber suspension.
Disk refiners are used to separate the individual fibers within the fiber suspension and/or to clean foreign matter such as dirt, etc. from the fiber suspension. A disk refiner typically includes a pair of opposing disks, with one or both of the disks being rotatable relative to each other. Each disk carries a plate, also known as a xe2x80x9ctacklexe2x80x9d, having a plurality of teeth mounted thereon. The shape of the teeth, as well as the angular orientation of the teeth define the particular processing action which the tackle effects on the fibers within fiber suspension. For example, the teeth may be configured and positioned on the tackle to provide a cutting action or a brushing action to the fibers within the fiber suspension.
Typically, the teeth are arranged at different oblique angles relative to each other such that the fiber suspension changes flow directions as it flows from the inside diameter to the outside diameter of the tackle in the grooves between adjacent teeth. Although the changing flow directions result in effective refining of the fiber suspension, the changing flow directions also in essence cause a resistance to the flow through the tackle which in turn raises the input energy requirements for operation of the refiner.
What is needed in the art is a refiner for a fiber suspension which provides a higher throughput rate with lower energy requirements. What is further needed in the art is a refiner which provides effective but yet gentle refining of the fiber suspension.
The present invention provides a refiner for refining a fiber suspension with a tackle having concentric rows of teeth which are subdivided into quadrants, and further subdivided into sectors within each quadrant, such that the sectors define substantially unimpeded flow-through channels allowing the fiber suspension to flow from the inside diameter to the outside diameter of the tackle.
The invention comprises, in one form thereof, a refiner for refining a fiber suspension, including a first disk which is rotatable or stationary, and a second disk which is rotatable. A first tackle is coupled with a first disk or the second disk. A second tackle is coupled with the other of the first disk or second disk. The second tackle includes a plurality of generally annular rows of teeth with a radially inner row and a radially outer row. Adjacent teeth within a same row are separated by a groove therebetween. Adjacent rows are concentrically spaced by a generally annular gap therebetween. The concentrically spaced rows are divided into a plurality of adjacent sectors, with each sector having opposing side edges extending through and between the radially inner row and the radially outer row to define a substantially unimpeded flow-through channel for the fiber suspension.
An advantage of the present invention is that the unimpeded flow-through channels allow the refiner to be operated with lower energy input requirements.
Another advantage is that the throughput rate of the fiber suspension through the refiner is increased.
Yet another advantage is that the teeth may be configured with a desired cross sectional shape to perform various refining functions on the fiber suspension, while at the same time still maintaining a higher throughput rate and lower input energy requirement.
A further advantage is that a relatively gentle refining action is carried out on the fiber suspension within the refiner.